A wind turbine comprises several components like a tower, a nacelle, a generator, a rotor comprising a hub and rotor blades and so on. To build up the wind turbine these partially very heavy components must be mounted with each other.
So before the rotor is raised and mounted on the nacelle, it is assembled at the ground. Thereby each rotor blade is mounted on a respective rotor blade bearing located at the hub with a lot of bolts, which have to pass through bolt holes of a rotating part of the rotor blade bearing. The rotating part of each rotor blade bearing has a certain swivel range or adjustment range for the adjustment of the pitch of the respective rotor blade mounted on that rotor blade bearing. Thus the rotor blade has to be mounted on the rotating part of the respective rotor blade bearing in a certain defined position that in later operation of the wind turbine the pitch of this rotor blade is correctly adjustable.
In the course of the mounting of a rotor blade on a rotor blade bearing therefore the rotor blade bearing has to be oriented, swivelled or turned e.g. with an electrical or hydraulic system to get the right position for mounting in relation to the orientation of the rotor blade. Additionally the rotor blade bearing has to be many times vibrated during the mounting to overcome the friction or slight deadlocks between the bolts of the rotor blade and the bolt holes of the rotating part of the rotor blade bearing.
In particular when a hydraulic system located in the hub is used for turning, swivelling or adjusting the rotating part of a rotor blade bearing during the operation of the wind turbine for the adjustment of the pitch of the rotor blade as well as during the mounting of the rotor blade and the rotor blade bearing of the hub with each other until now in the course of the mounting a lot of or all cables at hydraulic valves of the hydraulic system were removed from the hydraulic valves and a hydraulic adjustment device particularly cables of the hydraulic adjustment device were connected to the hydraulic valves. By controlling of the hydraulic adjustment device it was possible to turn, swivel or adjust the rotor blade bearing particularly the rotating part of the rotor blade bearing as required. This proceeding of removing of the cables of the hydraulic system from the hydraulic valves of the hydraulic system, of connecting of the hydraulic adjustment device to the valves and of reconnecting of the cables of the hydraulic system to the hydraulic valves after the mounting takes a lot of time. Furthermore there is a not negligible risk for connecting wrong cables of the hydraulic system to the hydraulic valves after the mounting as a result of mix-up.